add legacy fallback to RMNRemote (#15422)

* add legacy fallback to RMNRemote

* changeset

* [Bot] Update changeset file with jira issues

* allow address 0

* fix solhint

---------

Co-authored-by: app-token-issuer-infra-releng[bot] <120227048+app-token-issuer-infra-releng[bot]@users.noreply.github.com>

contracts/.changeset/bright-jokes-kiss.md

@@ -0,0 +1,10 @@
+---
+'@chainlink/contracts': patch
+---
+
+add legacy fallback to RMN
+
+
+PR issue: CCIP-4261
+
+Solidity Review issue: CCIP-3966

contracts/gas-snapshots/ccip.gas-snapshot

@@ -573,27 +573,27 @@ RMNHome_validateStaticAndDynamicConfig:test_validateStaticAndDynamicConfig_Dupli
 RMNHome_validateStaticAndDynamicConfig:test_validateStaticAndDynamicConfig_NotEnoughObservers_reverts() (gas: 21405)
 RMNHome_validateStaticAndDynamicConfig:test_validateStaticAndDynamicConfig_OutOfBoundsNodesLength_reverts() (gas: 137318)
 RMNHome_validateStaticAndDynamicConfig:test_validateStaticAndDynamicConfig_OutOfBoundsObserverNodeIndex_reverts() (gas: 20522)
-RMNRemote_constructor:test_constructor_success() (gas: 8334)
-RMNRemote_constructor:test_constructor_zeroChainSelector_reverts() (gas: 59184)
-RMNRemote_curse:test_curse_AlreadyCursed_duplicateSubject_reverts() (gas: 154479)
-RMNRemote_curse:test_curse_calledByNonOwner_reverts() (gas: 18712)
-RMNRemote_curse:test_curse_success() (gas: 149431)
-RMNRemote_global_and_legacy_curses:test_global_and_legacy_curses_success() (gas: 133512)
+RMNRemote_constructor:test_constructor() (gas: 8398)
+RMNRemote_curse:test_curse_AlreadyCursed_duplicateSubject_reverts() (gas: 154501)
+RMNRemote_curse:test_curse_calledByNonOwner_reverts() (gas: 18734)
+RMNRemote_curse:test_curse_success() (gas: 149475)
+RMNRemote_global_and_legacy_curses:test_global_and_legacy_curses_success() (gas: 133441)
+RMNRemote_isBlessed:test_isBlessed() (gas: 17588)
 RMNRemote_setConfig:test_setConfig_ZeroValueNotAllowed_revert() (gas: 37971)
 RMNRemote_setConfig:test_setConfig_addSigner_removeSigner_success() (gas: 993448)
 RMNRemote_setConfig:test_setConfig_duplicateOnChainPublicKey_reverts() (gas: 323540)
 RMNRemote_setConfig:test_setConfig_invalidSignerOrder_reverts() (gas: 80201)
 RMNRemote_setConfig:test_setConfig_notEnoughSigners_reverts() (gas: 54232)
-RMNRemote_uncurse:test_uncurse_NotCursed_duplicatedUncurseSubject_reverts() (gas: 51993)
-RMNRemote_uncurse:test_uncurse_calledByNonOwner_reverts() (gas: 18682)
-RMNRemote_uncurse:test_uncurse_success() (gas: 40171)
-RMNRemote_verify_withConfigNotSet:test_verify_reverts() (gas: 13578)
-RMNRemote_verify_withConfigSet:test_verify_InvalidSignature_reverts() (gas: 96449)
-RMNRemote_verify_withConfigSet:test_verify_OutOfOrderSignatures_duplicateSignature_reverts() (gas: 94267)
-RMNRemote_verify_withConfigSet:test_verify_OutOfOrderSignatures_not_sorted_reverts() (gas: 101330)
-RMNRemote_verify_withConfigSet:test_verify_ThresholdNotMet_reverts() (gas: 304634)
-RMNRemote_verify_withConfigSet:test_verify_UnexpectedSigner_reverts() (gas: 428126)
-RMNRemote_verify_withConfigSet:test_verify_success() (gas: 86159)
+RMNRemote_uncurse:test_uncurse_NotCursed_duplicatedUncurseSubject_reverts() (gas: 51940)
+RMNRemote_uncurse:test_uncurse_calledByNonOwner_reverts() (gas: 18615)
+RMNRemote_uncurse:test_uncurse_success() (gas: 40135)
+RMNRemote_verify_withConfigNotSet:test_verify_reverts() (gas: 13600)
+RMNRemote_verify_withConfigSet:test_verify_InvalidSignature_reverts() (gas: 96471)
+RMNRemote_verify_withConfigSet:test_verify_OutOfOrderSignatures_duplicateSignature_reverts() (gas: 94289)
+RMNRemote_verify_withConfigSet:test_verify_OutOfOrderSignatures_not_sorted_reverts() (gas: 101352)
+RMNRemote_verify_withConfigSet:test_verify_ThresholdNotMet_reverts() (gas: 304744)
+RMNRemote_verify_withConfigSet:test_verify_UnexpectedSigner_reverts() (gas: 428284)
+RMNRemote_verify_withConfigSet:test_verify_success() (gas: 86181)
 RateLimiter_constructor:test_Constructor_Success() (gas: 19806)
 RateLimiter_consume:test_AggregateValueMaxCapacityExceeded_Revert() (gas: 16042)
 RateLimiter_consume:test_AggregateValueRateLimitReached_Revert() (gas: 22435)

contracts/src/v0.8/ccip/rmn/RMNRemote.sol

@@ -2,6 +2,7 @@
 pragma solidity 0.8.24;
 
 import {ITypeAndVersion} from "../../shared/interfaces/ITypeAndVersion.sol";
+import {IRMN} from "../interfaces/IRMN.sol";
 import {IRMNRemote} from "../interfaces/IRMNRemote.sol";
 
 import {Ownable2StepMsgSender} from "../../shared/access/Ownable2StepMsgSender.sol";
@@ -19,7 +20,10 @@ bytes16 constant LEGACY_CURSE_SUBJECT = 0x01000000000000000000000000000000;
 bytes16 constant GLOBAL_CURSE_SUBJECT = 0x01000000000000000000000000000001;
 
 /// @notice This contract supports verification of RMN reports for any Any2EVM OffRamp.
-contract RMNRemote is Ownable2StepMsgSender, ITypeAndVersion, IRMNRemote {
+/// @dev This contract implements both the new IRMNRemote interface and the legacy IRMN interface. This is to allow for
+/// a seamless migration from the legacy RMN contract to this one. The only function that has been dropped in the newer
+/// interface is `isBlessed`. For the `isBlessed` function, this contract relays the call to the legacy RMN contract.
+contract RMNRemote is Ownable2StepMsgSender, ITypeAndVersion, IRMNRemote, IRMN {
   using EnumerableSet for EnumerableSet.Bytes16Set;
 
   error AlreadyCursed(bytes16 subject);
@@ -33,6 +37,7 @@ contract RMNRemote is Ownable2StepMsgSender, ITypeAndVersion, IRMNRemote {
   error ThresholdNotMet();
   error UnexpectedSigner();
   error ZeroValueNotAllowed();
+  error IsBlessedNotAvailable();
 
   event ConfigSet(uint32 indexed version, Config config);
   event Cursed(bytes16[] subjects);
@@ -67,6 +72,7 @@ contract RMNRemote is Ownable2StepMsgSender, ITypeAndVersion, IRMNRemote {
 
   string public constant override typeAndVersion = "RMNRemote 1.6.0-dev";
   uint64 internal immutable i_localChainSelector;
+  IRMN internal immutable i_legacyRMN;
 
   Config private s_config;
   uint32 private s_configCount;
@@ -80,11 +86,11 @@ contract RMNRemote is Ownable2StepMsgSender, ITypeAndVersion, IRMNRemote {
   mapping(address signer => bool exists) private s_signers; // for more gas efficient verify.
 
   /// @param localChainSelector the chain selector of the chain this contract is deployed to.
-  constructor(
-    uint64 localChainSelector
-  ) {
+  constructor(uint64 localChainSelector, IRMN legacyRMN) {
     if (localChainSelector == 0) revert ZeroValueNotAllowed();
     i_localChainSelector = localChainSelector;
+
+    i_legacyRMN = legacyRMN;
   }
 
   // ================================================================
@@ -248,7 +254,7 @@ contract RMNRemote is Ownable2StepMsgSender, ITypeAndVersion, IRMNRemote {
   }
 
   /// @inheritdoc IRMNRemote
-  function isCursed() external view returns (bool) {
+  function isCursed() external view override(IRMN, IRMNRemote) returns (bool) {
     // There are zero curses under normal circumstances, which means it's cheaper to check for the absence of curses.
     // than to check the subject list twice, as we have to check for both the legacy and global curse subjects.
     if (s_cursedSubjects.length() == 0) {
@@ -260,12 +266,28 @@ contract RMNRemote is Ownable2StepMsgSender, ITypeAndVersion, IRMNRemote {
   /// @inheritdoc IRMNRemote
   function isCursed(
     bytes16 subject
-  ) external view returns (bool) {
+  ) external view override(IRMN, IRMNRemote) returns (bool) {
     // There are zero curses under normal circumstances, which means it's cheaper to check for the absence of curses.
     // than to check the subject list twice, as we have to check for both the given and global curse subjects.
     if (s_cursedSubjects.length() == 0) {
       return false;
     }
     return s_cursedSubjects.contains(subject) || s_cursedSubjects.contains(GLOBAL_CURSE_SUBJECT);
   }
+
+  // ================================================================
+  // │                     Legacy pass through                      │
+  // ================================================================
+
+  /// @inheritdoc IRMN
+  /// @dev This function is only expected to be used for messages from CCIP versions below 1.6.
+  function isBlessed(
+    TaggedRoot calldata taggedRoot
+  ) external view returns (bool) {
+    if (i_legacyRMN == IRMN(address(0))) {
+      revert IsBlessedNotAvailable();
+    }
+
+    return i_legacyRMN.isBlessed(taggedRoot);
+  }
 }

contracts/src/v0.8/ccip/test/rmn/RMNRemote/RMNRemote.constructor.t.sol

@@ -1,16 +1,10 @@
 // SPDX-License-Identifier: BUSL-1.1
 pragma solidity 0.8.24;
 
-import {RMNRemote} from "../../../rmn/RMNRemote.sol";
 import {RMNRemoteSetup} from "./RMNRemoteSetup.t.sol";
 
 contract RMNRemote_constructor is RMNRemoteSetup {
-  function test_constructor_success() public view {
+  function test_constructor() public view {
     assertEq(s_rmnRemote.getLocalChainSelector(), 1);
   }
-
-  function test_constructor_zeroChainSelector_reverts() public {
-    vm.expectRevert(RMNRemote.ZeroValueNotAllowed.selector);
-    new RMNRemote(0);
-  }
 }

contracts/src/v0.8/ccip/test/rmn/RMNRemote/RMNRemote.isBlessed.t.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity 0.8.24;
+
+import {IRMN} from "../../../interfaces/IRMN.sol";
+
+import {RMNRemote} from "../../../rmn/RMNRemote.sol";
+import {RMNRemoteSetup} from "./RMNRemoteSetup.t.sol";
+
+contract RMNRemote_isBlessed is RMNRemoteSetup {
+  function test_isBlessed() public {
+    IRMN.TaggedRoot memory taggedRoot = IRMN.TaggedRoot({root: keccak256("root"), commitStore: makeAddr("commitStore")});
+
+    vm.mockCall(
+      address(s_legacyRMN), abi.encodeWithSelector(s_legacyRMN.isBlessed.selector, taggedRoot), abi.encode(true)
+    );
+
+    assertTrue(s_rmnRemote.isBlessed(taggedRoot));
+
+    vm.mockCall(
+      address(s_legacyRMN), abi.encodeWithSelector(s_legacyRMN.isBlessed.selector, taggedRoot), abi.encode(false)
+    );
+
+    assertFalse(s_rmnRemote.isBlessed(taggedRoot));
+  }
+
+  function test_isBlessed_RevertWhen_IsBlessedNotAvailable() public {
+    IRMN.TaggedRoot memory taggedRoot = IRMN.TaggedRoot({root: keccak256("root"), commitStore: makeAddr("commitStore")});
+
+    s_rmnRemote = new RMNRemote(100, IRMN(address(0)));
+
+    vm.expectRevert(RMNRemote.IsBlessedNotAvailable.selector);
+    s_rmnRemote.isBlessed(taggedRoot);
+  }
+}

contracts/src/v0.8/ccip/test/rmn/RMNRemote/RMNRemoteSetup.t.sol

@@ -1,7 +1,9 @@
 // SPDX-License-Identifier: BUSL-1.1
 pragma solidity 0.8.24;
 
+import {IRMN} from "../../../interfaces/IRMN.sol";
 import {IRMNRemote} from "../../../interfaces/IRMNRemote.sol";
+
 import {Internal} from "../../../libraries/Internal.sol";
 import {RMNRemote} from "../../../rmn/RMNRemote.sol";
 import {BaseTest} from "../../BaseTest.t.sol";
@@ -21,9 +23,11 @@ contract RMNRemoteSetup is BaseTest {
   bytes16 internal constant CURSE_SUBJ_2 = bytes16(keccak256("subject 2"));
   bytes16[] internal s_curseSubjects;
 
+  IRMN internal s_legacyRMN = IRMN(makeAddr("legacyRMN"));
+
   function setUp() public virtual override {
     super.setUp();
-    s_rmnRemote = new RMNRemote(1);
+    s_rmnRemote = new RMNRemote(1, s_legacyRMN);
     OFF_RAMP_ADDRESS = makeAddr("OFF RAMP");
     s_curseSubjects = [CURSE_SUBJ_1, CURSE_SUBJ_2];
 

core/gethwrappers/ccip/generation/generated-wrapper-dependency-versions-do-not-edit.txt

@@ -23,7 +23,7 @@ registry_module_owner_custom: ../../../contracts/solc/v0.8.24/RegistryModuleOwne
 report_codec: ../../../contracts/solc/v0.8.24/ReportCodec/ReportCodec.abi ../../../contracts/solc/v0.8.24/ReportCodec/ReportCodec.bin 6c943b39f003aa67c3cefa19a8ff99e846236a058e1ceae77569c3a065ffd5c7
 rmn_home: ../../../contracts/solc/v0.8.24/RMNHome/RMNHome.abi ../../../contracts/solc/v0.8.24/RMNHome/RMNHome.bin 84ca84b3d0c00949905a3d10a91255f877cf32b2a0d7f7f7ce3121ced34a8cb7
 rmn_proxy_contract: ../../../contracts/solc/v0.8.24/ARMProxy/ARMProxy.abi ../../../contracts/solc/v0.8.24/ARMProxy/ARMProxy.bin b048d8e752e3c41113ebb305c1efa06737ad36b4907b93e627fb0a3113023454
-rmn_remote: ../../../contracts/solc/v0.8.24/RMNRemote/RMNRemote.abi ../../../contracts/solc/v0.8.24/RMNRemote/RMNRemote.bin faee0b0cdbe67f2e28deccf12acd4df13dd90992f6cbc0ba17bab845b8f4eb1c
+rmn_remote: ../../../contracts/solc/v0.8.24/RMNRemote/RMNRemote.abi ../../../contracts/solc/v0.8.24/RMNRemote/RMNRemote.bin 941118dfdc6bb042c339cfe8d8e0c7a0b486afb731a785d58a64994e7a13c459
 router: ../../../contracts/solc/v0.8.24/Router/Router.abi ../../../contracts/solc/v0.8.24/Router/Router.bin 2e4f0a7826c8abb49d882bb49fc5ff20a186dbd3137624b9097ffed903ae4888
 token_admin_registry: ../../../contracts/solc/v0.8.24/TokenAdminRegistry/TokenAdminRegistry.abi ../../../contracts/solc/v0.8.24/TokenAdminRegistry/TokenAdminRegistry.bin 397bc7be08c2848c0f4715f90b16206d6367f78ffb7cd48e2b1dfc0ccc5aea26
 token_pool: ../../../contracts/solc/v0.8.24/TokenPool/TokenPool.abi ../../../contracts/solc/v0.8.24/TokenPool/TokenPool.bin da86a1407f31134e7246bde63c80ce8c78ce7d7b44e267f3c1f6030441ff4252

deployment/ccip/changeset/deploy.go

@@ -7,9 +7,10 @@ import (
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
-	cciptypes "github.com/smartcontractkit/chainlink-ccip/pkg/types/ccipocr3"
 	"golang.org/x/sync/errgroup"
 
+	cciptypes "github.com/smartcontractkit/chainlink-ccip/pkg/types/ccipocr3"
+
 	"github.com/smartcontractkit/chainlink/deployment/ccip/changeset/internal"
 
 	"github.com/smartcontractkit/chainlink/deployment"
@@ -599,6 +600,8 @@ func deployChainContracts(
 					chain.DeployerKey,
 					chain.Client,
 					chain.Selector,
+					// Indicates no legacy RMN contract
+					common.HexToAddress("0x0"),
 				)
 				return deployment.ContractDeploy[*rmn_remote.RMNRemote]{
 					rmnRemoteAddr, rmnRemote, tx, deployment.NewTypeAndVersion(RMNRemote, deployment.Version1_6_0_dev), err2,